期刊
CELLULAR SIGNALLING
卷 22, 期 5, 页码 749-758出版社
ELSEVIER SCIENCE INC
DOI: 10.1016/j.cellsig.2009.12.010
关键词
Statin; Breast tumor; Bcl(XL); Akt kinase
类别
资金
- NIH [RO1 AR52425, RO1 DK50190]
- VA Research Service Merit Review
- Department of Veterans Affairs
- Juvenile Diabetes Research Foundation [1-2008-185]
Sustained activation of Akt kinase acts as a focal regulator to increase cell growth and survival, which causes tumorigenesis including breast cancer. Statins, potent inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, display anticancer activity. The molecular mechanisms by which statins block cancer cell growth are poorly understood. We demonstrate that in the tumors derived from MDA-MB-231 human breast cancer cell xenografts, simvastatin significantly inhibited phosphorylation of Akt with concomitant attenuation of the expression of the anti-apoptotic protein Bcl(XL). In many cancer cells, Bcl(XL) is a target of NF kappa B. Simvastatin inhibited the DNA binding and transcriptional activities of NF kappa B resulting in marked reduction in transcription of Bcl(XL). Signals transmitted by anti-neoplastic mechanism implanted in the cancer cells serve to obstruct the initial outgrowth of tumors. One such mechanism represents the action of the tumor suppressor protein PTEN, which negatively regulates Akt kinase activity. We provide the first evidence for significantly increased levels of PTEN in the tumors of simvastatin-administered mice. Importantly, simvastatin markedly prevented binding of NF kappa B to the two canonical recognition elements, NFRE-1 and NFRE-2 present in the PTEN promoter. Contrary to the transcriptional suppression of Bcl(XL), simmastatin significantly increased the transcription of PTEN. Furthermore, expression of NF kappa B p65 subunit inhibited transcription of PTEN, resulting in reduced protein expression, which leads to enhanced phosphorylation of Akt. Taken together, our data present a novel bifaceted mechanism where simmastatin acts on a nodal transcription factor NF kappa B, which attenuates the expression of anti-apoptotic Bcl(XL) and simultaneously derepresses the expression of anti-proliferative/proapoptotic tumor suppressor PTEN to prevent breast cancer cell growth. Published by Elsevier Inc.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据